Objective To analyze the methylation status of MUC2 gene in pancreatic carcinoma cell lines and peripheral blood of pancreatic carcinoma patients,and to explore the role of MUC2 methylation in the early diagnosis of pancreatic carcinoma.Methods Human pancreatic cancer cell lines of SW1990,ASPC,PANC1,BxPC3,PaTu8988 and CFPAC1,and 40 peripheral blood samples of pancreatic carcinoma patients,15 cases of chronic pancreatitis,25 cases of normal controls were collected,and the methylation status of MUC2 gene was detected by methylation sensitive restriction endonuclease PCR.Results MUC2 methylation was not detected in PANC1,BxPC3,PaTu8988,but was detected in ASPC,CFPAC1,SW1990.Among the peripheral blood samples,the rate of methylation in pancreatic cancer was 40.O%(n=16),in chronic pancreatitis was 0%,in normal controls was 4.0%(n=1),and the difference among the three groups was statistically significant(P＜0.01).The methylation of MUC2 gene CpG islands for the diagnosis of pancreatic carcinoma had a sensitivity of 40%,specificity of 97.5%,accuracy of 68.8%,positive predictive value of 94.1%and negative predictive value of 61.9%.Conclusions The detection of MUC2 hypermethylation in peripheral blood samples may be an potential marker for early diagnosis of pancreatic carcinoma.

Objective To study the diagnostic value of endoscopic ultrasonography (EUS)for benign and malignant bile duct stricture.Methods Data of 51 patients who underwent EUS from January 2007 to March 2015 due to distal biliary stricture were retrospectively studied.And their diagnosis with EUS,IDUS,bile duct cytological brushing and final diagnosis were compared.Results Malignant bile duct stenosis were finally confirmed in 19 cases and benign stenosis were confirmed in 32 cases.The sensitivity (73.7％ VS 57.1％) and positive predictive value (73.7％ VS 57.1％) of EUS for the benign and malignant diagnosis of biliary tract stenosis were significantly higher than that of IDUS (P＜0.05),while their specificity(84.4％ VS 84.2％)and accuracy(80.4％ VS 76.9％)were similar.The sensitivity of EUS was significantly higher than that of bile duct cytological brushing (73.7％ VS 50.0％),while their specificity (84.4％ VS 100.0％)and accuracy(80.4％ VS 81.6％)were similar.EUS findings of hypoechoic mass features had higher diagnostic accuracy for detecting malignant distal bile duct stricture than irregular thickening of the lumen in the distal bile duct (100.0％ VS 64.3％,P＜0.05).Conclusion For patients with lesions of the distal bile duct that CT/MRI could not diagnose,EUS has an important value for the further diagnosis of benign and malignant bile duct stricture.

Long-COVID-19 syndrome（LCS）is a multisystem and chronic disease caused by SARS-CoV-2，which can be attributed to the disorder of gut microbiota.Compared to healthy individuals，patients with LCS have different microbial communities，which can last for some time.The distribution of gut microbiota is different.Potential mechanisms that affect LCS may be related to gut-lung axis，gut-brain axis，potential pathogenic bacterias，microbial metabolites，etc.Prevention and treatment about LCS based on gut microbiota mainly contain probiotics，prebiotics，fecal microbiota transplantation，etc.Clarifying the relationship and pathogenesis between gut microbiota and LCS may contribute to early diagnosis and the research for new biological targets.